Well... I'm not sure whether this is worth a thread as it's quite unrealistic. But there are so many FD lenses you can't really use any more and sometimes I think something like "Why the heck don't they build ONE FD compatible DSLR?". It doesn't have to be spectacular. Something like a 6D without AF, WiFi and GPS and with another focussing screen. I guess there are quite a lot of people who would buy it. There are still so many FD lenses out there and using adapters isn't really such a great solution if you are using EOS cameras. They wouldn't have to create many different cameras, just once one simple digital camera that works.

If the camera had the same price as the 6D they could still make money with it. People who use EF lenses wouldn't change and those with EF lenses would buy such a camera. Only few would think of getting a camera that has no AF over a camera with AF for the same price - if fitting lenses aren't available, yet. And the cost for development could be much lower as well - just take an existing camera, change the mount, remove a few features and sell it as another camera.

It wasn't until recently I found out full frame EF body mirrors can hit the back of a FD lens if you adapt it to fit at the correct distance for infinity focus. So it will be more work than you think to make a new FD body. Also I don't really see many people buying an expensive body just to use old cheap(er) lenses. If the specific FD lens was special enough, then it might be worth the expense and effort of a mount conversion on it to use with a new body.